Industrial automation uses many control devices. One useful control device is a solenoid valve manifold, often simply referred to as a valve manifold, that houses a plurality of electrically actuated solenoid valves. The solenoid valves control the direction of hydraulic or pneumatic flow for actuating other downstream field devices, for example process valves. These valve manifolds have communication modules that often mount adjacent the solenoid valve stations, and connect to various fieldbus networks.
These fieldbus networks have become commonplace in automation control. The fieldbus network provides remote control over the valve stations. Typical fieldbus networks may use EtherNet/IP™, FIPIO™, Interbus-S™, ControlNet™ DeviceNet™ or other proprietary or open network protocols. The valve manifold is connected to a fieldbus network usually mastered by a remote programmable logic controller (PLC), industrial personal computer (IPC), and/or distributed control system (DCS). As used herein, the term distributed control system (DCS) is generic in nature and also includes PLCs and IPCs.
It is also common to have side by side network architecture as illustrated in FIG. 1, i.e., a fieldbus 11 that is connected to the valve manifold is parallel to another fieldbus network 13 with respect to a DCS 18. The DCS 18 may be a commercially available DeltaV™ DCS. A bank of Input/Output modules (I/O bank) 14, that uses a proprietary Ethernet connection as an example, is connected remotely from the DCS 18 to ethernet master unit 15 in the DCS 18. The I/O bank may be a commercially available CHARM™ I/O bank 14 connected to a plurality of field devices, i.e. sensors 24 that send back signals for various parameters sensed at process valves 44 or loads that may include valves. The I/O bank 14 can receive signals from the sensors and relays the signals in the fieldbus network 13 to the DCS 18. Valve manifolds 10 are connected to a master unit 12 in DCS 18. Valve manifold 10 is pneumatically operably connected to the plurality of process valves 44. The valve manifold 10 is connected in parallel to the DCS 18 relative to the I/O bank 14 via a different network 11, e.g. Profibus-DP. Both master unit 12 and ethernet network master 15 are controlled by DCS 18. In this fashion, the valve manifold and I/O bank work in parallel, side by side, using their own respective fieldbus networks 11 and 13 and respective protocols.
This standard prior art system uses one protocol network for controlling the valves, but uses another network to verify valve positions and other parameters via sensors. The use of two networks to coordinate the valves and sensors adds a level of undesirable complexity.
Coordination of valve and I/O control can be achieved by connecting each valve manifold station through a CHARM I/O module, each module having with its own microprocessor. This connection method, however, is expensive and labor intensive by the need to wire a separate CHARM I/O module with its own microprocessor to each solenoid valve of each valve station on the manifold.
What is needed is a more expeditious arrangement where the valve manifold is connected to the I/O bank 14 and logically becomes an integral part of the I/O bank as if the valves where physically part of the I/O bank such that the DCS can control the valve manifold and I/O bank as if they were one unit, using the I/O bank's existing backplane protocol and also allowing the DCS to decode diagnostic information available via the valve manifold's communication module for the valves and manifold system.